Instrument for laying out the edges of cutter-head knives.



G. W. YUN G.

INSTRUMENT FOR LAYING OUT THE EDGES OF CUTTER HEAD KNIVES.

APPLICATION FILED MAR. 26, 1913. 1,090,006.

Patented Mar. 10, 1914.

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G. W. YUNG.

INSTRUMENT FOR LAYING 0111." THE EDGES 0F CUTTER HEAD KNIVES.

APPLICATION FILED MAR. 26. 1913.

Patented Mar. 10, 1914.

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GEORGE W. YUNG, OF DUNKIRK, NEW YORK.

INSTRUMENT FOR LAYINGOUT THE EDGES OF CUTTER-HEAD KNIVES.

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To all 1071,0112. it may concern Be it known that I, GEORGE l/V. YUNG, acitizen of the United States, residing at Dunkirk, in the county ofChautauqua and State of New York, have invented certain new and usefulImprovements in Instruments for Laying Out the Edges of Cutter- HeadKnives, of which the following is a specification.

The object of this invention is to provide simple and reliable means forlaying out the cutting edges of the knives used on rotary cutter-headsto produce moldings of different patterns.

My invention is particularly intended for use in the formation of theknives of rotary cutters having what are known as square or polygonalheads on which the knives are arranged tangentially relatively to theaxis of rotation. In such cutters when used to produce moldings theknives being arranged tangentially on the head act on the stock at anangle and hence the different parts of the irregular cutting edge aredisposed in different vertical planes when the knife enters the stock.Consequently the recesses in the cutting edge must be deeper than theheight of the corresponding raised parts of the moldings and the depthsof these recesses must increase proportionately. This is well understoodby those skilled in the art and great difficulty is usually experiencedin laying out the edges of knives of this class in order to adapt themto produce moldings of the desired patterns. It is most commonly done atpresent by successive trials and grindings until the required edge isproduced, although instruments have heretofore been suggested forfacilitating to some extent the operation. I have produced an instrumentof very simple construction which enables me to determine without theuse of scales or similar measuring means and with absolute accuracy therequired dimensions for the pattern of a knife to produce any kind ofmolding by means of a rotary cutter-head of the type before mentioned.

The manner in which the instrument is preferably constructed andoperated is hereinafter explained, but many of the details ofconstruction may be changed or varied without departing from the broadfeatures of the improvement which are pointed out in the claims.

In the accompanying drawings :Figure Specification of Letters Patent.

Application filed March 26, 1913.

Patented Mar. Tilt), 1914.

Serial .No. 757,001.

1 is a perspective view of the preferred form of my instrument. Fig. 2is a plan View of the base-plate with the measuring rod shown by dottedlines, and partly broken away. Fig. 3 a plan view of the miasuring rod.Fig. {i is a view partly in side elevation, partly in longitudinalsection, and with parts broken away, of the measuring rod as preferablyconstructed. Fig. 5 is a diagram illustrating a piece of molding invertical section, and a knife of a square cutter-head having its edgeproperly formed to produce the molding. Fig. (5 is a plan view of themeasuring rod on an enlarged scale. showing more fully the devices forvarying its length. Fig. 7 shows a section on the line 7-7 of Fig. (3.

The instrument comprises a base-plate A, and a measuring rod B which ispivotally connected with the base-plate at a point a (Fig. 2)representing the center of rotation of the cutter-head to which theknife is applied. On the base-plate is marked a line 2 which would, ifproduced, pass through said point a. The base-plate is also marked at 7to represent a line registering with the plane of the inner face of theknife and also passing through the adjacent corner of the cutter-head.The line is technically called the knife line and the lines a and 12meet at a point corresponding with the cornor of "the cutter-head at anangle of 45. At r0 means is provided, such as a dot, to indicate orrepresent the edge of the knife or a point on the knife line yintersected by a clearance line a.

The measuring rod B may be provided with a knob Z) to serve as a handleand said rod is provided with means such as a shoulder 7) to assist inthe measuring operation as will be hereinafter described. Said rod isalso provided with means such as a straight edge 0 for indicating astraight line radial to the center of rotation and which may be made toregister with the radial line .2, in the manner shown in Figs. 1 and 2.

Figs. 1 and 2 indicate how the instrument may be adapted for use inlaying out the knives for cutter-heads of different sizes. The lines Z,m, n, 0. p, I r, s, t, w indicate cutter-heads of different sizes. Thusthe square within the lines Z, r, u, 0 may indicate a 3 head. The nextsquare may indicate a 3%" head, and so forth. Any sizes of heads may beindicated in this way and the instrument is adapted for use inconnection with heads of all sizes. When thus used the base-plate isprovided with additional pivot holes a, a a corresponding in position tothe centers of rotation of the different heads, and the measuring rod isprovided with corresponding additional holes cl, d (Z The pivotalconnection between the measuring rod and the base-plate may be made inany suitable way, as by a screw E.

It is sometimes desirable to lengthen and shorten the rod for thepurpose of adapting the measurements to diflerent amounts of clearancegiven to the knives. This may be done in various ways, but preferablyfor this purpose I form the rod in two parts, 19 b which aretelescopically connected with each other in the manner shown; that is tosay, the part b is formed with a tongue b which enters a groove 72 inthe part 6 The part b is formed with a slot 5 and through this slotextends a screw B which receives a clamp nut B. By these devices themeasuring rod may be lengthened or shortened and firmly connected. Ifdesired a scale B may be employed.

In Fig. 5 I have shown a well known form of molding M. In order to layout the pattern for the cutting edge of the knife K for producing thismolding by the use of my instrument, I proceed as follows: Measurementsare taken on the lines 12, 34, 5-6, 7 8, 910 in the manner indicated.For taking the measurement 910 for example, I proceed as follows: Imeasure from the base line of the molding along the line 910 by means ofdividers, calipers or other suitable instruments, indicated at D in Fig.1, and then bring the edge 0 of the measuring rod into register with theline 2, place one point of the dividers against the shoulder 6' and theother point against the straight edge 0 (Fig. 1). I then turn the rod tothe right until the outer point of the dividers reaches the line y. Thispoint is indicated at e in Fig. 2. I then turn the measuring rod out ofthe way, retain the outer point of the dividers on the knife line 3 at eand move the other point until it registers with the point :0 on thebaseplate, which point corresponds with the edge of the knife and isalso located on the clearance line a which may also be indicated on thebase-plate. This extension of the dividers is just suflicient toindicate the increase in the depth of the recess to be made in theknife. This measurement is then indicated on the pattern or diagram, andinasmuch as it is assumed that the other measurements at 12, 3-4, etc,have been made and ad justed, the result will be that when themeasurements are recorded the knife pattern indicated in Fig. 5 will beproduced, which is of the exact shape required to produce the molding Mshown in the same figure. I have indicated on the drawings in Fig. 2 a

point marked 2 The distance between the point e and 1/ is equal to thedistance from Z) to the point 0, which is the same as the distance 9-10in Fig, 5. The distance between y and 00 indicates the increase in thedimensions and this distance or increase corresponds precisely with thedistance between the point 10 in Fig. 5 and the adjacent edge of theknife.

No scales or similar devices are used which would confine themeasurements to definite limits and the instrument is of the simplestcharacter, being adapted for use in connection with cutter-heads of allsizes.

It will be understood that it is not necessary to place all the marksand lines on the base-plate that I have shown in the drawings. Some ofthese can obviously be omitted and the measuring rod may be differentlyconstruct-ed.

I claim as my invention:

1. An instrument for laying out the edges of cutter-heads, comprising abase plate provided with means for indicating the center of rotation ofa cutter-head, means for indieating a radial line extending from saidcenter of rotation through a. corner of the cutter-head, means forindicating a knife line' extending at an angle of 45 at the corner ofthe cutter-head to said radial line, and means for indicating on saidknife line the line of clearance of the cutter, in combination with ameasuring rod pivotally connected with the base plate at the pointindicating the center of rotation of the cutter.- head and which isprovided with means for indicating a. line adapted to register with saidradial line and also with means for indicating a point which is adaptedto register with the point on said knife line intersected by saidclearance line.

2. An instrument for laying out the edges of cutter-heads, comprising abase plate provided with means for indicating the center of rotation ofa cutter-head, means for indieating a radial line extending from saidcenter of rotation through a corner of the cutter-head, means forindicating a knife line arranged at an angle at the corner of thecutterhead to said radial line, and means for indicating on said knifeline the line of clearance of the cutter, in combination with ameasuring rod pivotally connected with the base plate at the pointrepresenting the center of rotation of the cutter-head and which rod isprovided with a straight edge adapted to register with said radial lineand also with a shoulder which is adapted to register with said point onthe knife line intersected by the clearance line.

3. An instrument for laying out the edges of cutter-heads, comprising abase plate provided with means for indicating a knife line, means forindicating a radial line ex tending from a point representing the centerof rotation of the cutter-head through a corner thereof, means forindicating the clearance line of the cutter, and a measuring rodprovided with means for pivoting it to the base plate at differentpoints representing different centers of rotation of cutterheads ofdiflerent sizes and which rod is provided with means for indicating aline adapted to register with said radial line and also with means forindicating a point which traverses the clearance line of the cutter.

4. An instrument for laying out the edges of cutter-head knives,comprising a base plate provided with means for indicating the center ofrotation of a cutter-head, means for indicating a radial line extendingfrom said center of rotation through a corner of the cutter-head, meansfor indicating a knife line, and means for indicating on said knife linethe line of clearance of the cutter, and a measuring rod pivotallyconnectcu with the base plate at the point representing the center ofrotation of the cutterhead and which is provided with means forindicating a line adapted to register with said radial line and withmeans for indicating a point of measurement, and devices for adjustingthe length of said rod.

In testimony whereof, I have hereunto subscribed my name.

GEORGE W. YUNG. Witnesses J. H. BOLLIN, J12, M. C. TALLY.

Copies of this patent may be obtained for five cents each, by addressingthe "Commissioner of Patents,

. Washington, D. 0.

